Propeller



July 31, 1923.

R. PIKE PROPELLER Filed Dec. 10, 1921 6 M p AC WA ma M a V; B an 1O \N F? IO M I; L

figl, WM @Mz A TTORNEYS suit I obtain by a sp Patented July 31, 1923.

UNITED STATES 1,463,447 PATENT OFFICE.

RICHARD PIKE, 01' 8'1. JOHN'S, NEWFOUNDLAND.

' mmm.

Application filed December 10, 1921. Serial No. 521,278.

To all whome't Be it known ject of the Kin resident of St. J?) invented certain new ments in Propellers, in is a specification.

y invention relates to propellers, particularly for ships, and has for its object to provide a device of this character which will combine great simplicity and strength with an efliciency eonsiderabl superior to that of ordinary screw-propel ers. This reecial novel arrangement of propeller blades in pairs, the blades of the same pair being arranged one in front of the other in the peculiar manner set forth hereinafter whereby the ressure of the water thrust backward by t e forward blade will be utilized in driving the rear blade.

Without desiring to restrict myself to the specific embodiment illustrated, will now proceed to describe, as an example, the form of my improved propeller shown in the accompanyin rear elevation of the side elevation thereof,

concern; that I, RICHARD PIKE, a subof Great Britain, and a hns, Newfoundland, have and useful Improveof which the followpropeller- Fig. 2 is a showing Also the propeller shaft and the stern of the ship; ig.

. propriate we or the y, In th one pair of blades is 3 is a section substantially on line 3-3 of g. 1; Fig. diagrammatic developed view illustrating the distances between corres ndin points of the blades of the same pair, at t e edges of such blades.

. In Fi 2, A indicates the stern of a ship, and B t e propeller shaft, with an arrow showing the direction in which said shaft rotates normally, that is to say, during forward motion of the ship. on this shaft a hub C is secured in an suitable manner, and the blades are fasten to this hub in any apmight be made integral therewith. e particular example illustrated, I have shown four E, arran d in two pairs, D- E and D, E respectively, the blades D, being the forward blades, that is, nearer the stern A, while the blades E, E are the rear blades. As will be seen best by reference to Fig. 1, equidistant from the other pair, measured circumferentiall that is to say, when there are two pairs of lades, these pairs are 180 apart, and the spacing would be different, but still equal or uniform, in case a greater number of ggirs were used. While, as stated, the blades D are 180 drawing, in which Fig. 1 is a 4 is a top view; and Fig. 5 is a bladesD, E,

relation obtains in regard to the blades E and E, the blades of the same pair are spaced or offset from. each other circumferentially, so that one of them will be in advance, with reference to the direction of rotation indicated by the arrow in Fig. 1, and according to my invention, this leadin blade is the rear blade E or E. The two blades of the same pair are portions of a pair of similar or arallel threads or s irals, and owing to one lade (the rear bla e) leading the other as set forth, said leading blade will overla or cover part of the surface .of the other blade (the following blade, or front blade) and according to my invention the amount of this overlapping is quite considerable, amounting to one half of the area of the blade, or more. It will be understood that each of the four blades is of the same character, that is, they are alike in pitch and in the form of their surfaces, and differ only in position. The lon 'tudinal radial) axes of the individual bla es, there ore, all form the same an is in the construction illustrated) with the axis of rotation. The overla pm referred, to above is to be unde'rstoo' as indicating the a pearance of the propeller to an observer 160 mg along the axis of the ropeller, from the rear, as in Fig. 1. T ore is also, as shown in Fig. 2, a certain amount of overlapping when the device is viewed from the side, or transversely ,of the axis, the distance between corresponding points of the blades of the same pair, measured alon the axis of rotation, being about equal to hal the width of the blades. The two rear blades E, E are at the same distance from the end of the shaft B, that is, the centers of said rear blades rotate in the same plane; similarly, the centers of the two front blades D D rotate in the same plane, which plane of course is nearer the stern A that is to say, in advance of the lane in which the centers of the blades E, El rotate- Fig. 5'illustrates, in a developed view, the distances between like points along the edges of the two blades of the same pair, and for the purpose of greater clearness, similar points alon such edges have been designated by like ettens in i 2 and 5. Owing to the sha of the blad s, this distance is least at t e inner portions of roots of the blades, and greatest at the outer portions or tips, where the blade edges are farthest from the axis of rotation.

apart, and a like .fuel consumption for the. same s A propeller constructed according to my invention, whether in the exact form illustrated or in other embodiments, is greatly superior to the usual screw propellers, an in particular, offers the following im rtan advantages: There is a remarkable ecrease in vibration, and therefore a very steady runnin of the propeller and of the shi There is also found (probably as the res t of such steady running) a great lowering of cod of the ship, and an increase m s d o from 5 to 10%, with the' same engine power. This improved 0 eration of my ropeller is due chiefly, I be ieve, to the high y advanta ous relative location of the two blades 0 the same pair. ith the arrangement described, the forward blade will, during the normal or forward travel of the shi thrust the water backward against the a jalcent rear blade, which, as stated, is the leading blade in that case, and the energy of this flow of water is thus utilized in driving the rear blade.

The normally active or the normall inactive or rear surface of a blade whic latter surface becomes active when t e ropeller is reversed), may be of substantia ly similar character, as illustrated by Fig. 3.

While I have referred to my improved propeller as applied to the propulsion of water-craft (boats, ships, submarines, torpedoes, etc.), it may be used for the propulsion of air-craft as well. In special cases, a device of the character described might be used as a pump or a fan, or the device might be em loyed as a motor operated by a current 0 water, air, or other fluid. The blades preferably increase in width from their roots outwardly to a certain point, and then again decrease in width (measured circumferentially) gradually to their tips, but I desire it to be understood that various modifications may be made without departing from the nature of my invention as set forth in the szfpended claims.

I aim as my invention:

1. A device adapted for use as a propeller, consisting of a rotary structure comprising a hub and pairs of blades extending there from, said pairs being spaced equidistant t one blade will front surface, and,

circumferentially, the two blades of the same air forming portions of similar spirals and in ofi'set alonfi the axis of rotation by about half the w1 th of said blades, so that be in front of the other, the longitudinal axes of all the blades forming the same angle with the axis of rotation, the rear blades having their corresponding points in the same planes rpendicular to said axis, and the front bl es likewise having their corresponding points in the same lanes perpendicular to said axis,'the rear lade 0 each pair being ofiset circumferentially relatively to the front blade of the same pair and, when viewed in a direction along the axis of rotation, overlap ing such front blade by at least one-half of its area, the circumferential ofi'set bein in such direction that such rear blade wi be the leading blade, during the rotation of the device in the normal direction, to secure an efiicient consecutive contact of the fluid with the two blades of the same pair.

2. A device adapted for use as a propeller, consisting ofa rotary structure comprising airs of blades which pairs are sp in a circumferential direction the two blades of the same air being offset from each other bothcircum erentially and lengthwise of the axis of rotation, and cyclic. ping both when viewed along said axis an at right angles thereto, the direction of circumferential offset being such that when the device is rotating in the normal direction, the rear blade of eac pair will be the leading blade.

3. device adapted for use as a propeller, consisting of a rotary structure comprising pairs of blades which pairs are spaced evenl in a circumferential direction, the longtudinal axes of all the blades bein perpendicular to the axis of rotation, an the two blades of the same pair bein ofiset from each other both 1e hwise o the axis of rotation and circum erentially, the direction of circumferential ofiset being such t at when the device is notatirgg in the normal direction, the rear blade each pair will be the leading blade.

In testimony whereof I have signed this specification.

RICHARD PIKE.

evenly 

